rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=766c/1/0x4000000000000000 softirq=51090/51093 fqs=1 (detected by 0, t=10505 jiffies, g=73169, q=129 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 13253 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-00009-g5a41237ad1d4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: netns cleanup_net RIP: 0010:match_held_lock+0xc/0xc0 kernel/locking/lockdep.c:5114 Code: 02 ba ff e8 ba 78 ff ff 31 c0 48 83 c4 08 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 53 48 89 fb 48 83 ec 08 48 39 77 10 <74> 6a 66 f7 47 22 f0 ff 74 5a 48 8b 46 08 48 89 f7 48 85 c0 74 42 RSP: 0018:ffffc900001e0bb8 EFLAGS: 00000006 RAX: 000000000000000f RBX: ffff8880812827f0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8c7919c0 RDI: ffff8880812827f0 RBP: ffffffff8c7919c0 R08: 0000000000000000 R09: ffffffff8e72da57 R10: fffffbfff1ce5b4a R11: 0000000000000000 R12: ffff888081281d40 R13: ffff888081282778 R14: 00000000ffffffff R15: ffff8880812827f0 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555557274708 CR3: 0000000036d14000 CR4: 0000000000350ee0 Call Trace: __lock_is_held kernel/locking/lockdep.c:5409 [inline] lock_is_held_type+0xab/0x140 kernel/locking/lockdep.c:5711 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3e/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x5cf/0x810 kernel/locking/lockdep.c:5679 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1a/0x70 kernel/locking/spinlock.c:194 debug_object_activate+0x28b/0x3e0 lib/debugobjects.c:693 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x2b/0x470 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xc71/0xfb0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0x180/0x640 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x227/0x630 kernel/locking/lockdep.c:5636 Code: 8f 9e 7e 83 f8 01 0f 85 3a 03 00 00 9c 58 f6 c4 02 0f 85 25 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90004f1fa28 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920009e3f48 RCX: 69bc9c9e3226bf77 RDX: 1ffff110102504ee RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff91337ac7 R10: fffffbfff2266f58 R11: 1ffff110048b57da R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8c791a80 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:325 [inline] rcu_read_lock include/linux/rcupdate.h:764 [inline] inet_twsk_purge+0x132/0x8a0 net/ipv4/inet_timewait_sock.c:295 ops_exit_list+0x125/0x170 net/core/net_namespace.c:174 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:606 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g73169 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=63181 rcu: rcu_preempt kthread starved for 10500 jiffies! g73169 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:28184 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0xb8a/0x5450 kernel/sched/core.c:6555 schedule+0xde/0x1b0 kernel/sched/core.c:6631 schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1656 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1855 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 14645 Comm: kworker/u4:3 Not tainted 6.2.0-rc3-syzkaller-00009-g5a41237ad1d4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x20 kernel/kcov.c:304 Code: 00 00 f3 0f 1e fa 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 9a fe ff ff 66 2e 0f 1f 84 00 00 00 RSP: 0018:ffffc9000ac37970 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff8880b9941d60 RCX: ffffffff81765453 RDX: ffff8880812aba80 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10173283ad R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32238000 CR3: 000000000c48e000 CR4: 0000000000350ef0 Call Trace: csd_lock_wait kernel/smp.c:413 [inline] smp_call_function_many_cond+0x463/0x10a0 kernel/smp.c:987 on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:1155 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1772 [inline] text_poke_bp_batch+0x22e/0x6b0 arch/x86/kernel/alternative.c:1963 text_poke_flush arch/x86/kernel/alternative.c:2131 [inline] text_poke_flush arch/x86/kernel/alternative.c:2128 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2138 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:799 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:791 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308